Intermittent Erratic Speedo / Diagnostic Codes L and K

[ec1 eex]

My Speedo, both analog & digital are intermittently having a life of their own.
When playing up, the needle and the digital reading start dancing all over the place. It's adding miles onto the car even when I'm stationary at traffic lights. Even though I'm seeing peak speeds of >200mph, due to the nature of the speed being all over the place, I'm probably putting miles on at a rate of 50mph average when it happens.

In addition, I get Diagnostic code L and K appear, but only when the car stops and the needle comes to zero.

I did have the transducer looked at, but at the time the speedo wasn't playing around so the garage told me that they couldn't find a fault with it.

One annoying side effect is that I can't open the doors unless I turn the engine off when this is happening as the car thinks it's still moving.

Any ideas as to where my problem lies?

PS - I accidently left the lights on tonight & got a flat battery. When getting a jump start, the immobiliser wouldn't disarm (even with the "thing" pushed into the dash). Disconnecting the battery totally managed to reset this, but at the same time should have reset the ECU. Bad news - the speedo is still bouncing around.

[davido140]

I have a very rare occurence of the speedo dropping out and sometimes stalling when its cold with an error L (I think) was told if its not the transducer then the whole LCD needs replacing.

Is yours an early car? there were bugs in the software on early cars IIRC

[ec1 eex]

It's a March 2003 car, so shouldn't have any "early software issues"

I'm starting to think that either I've got a partially dry solder joint inside my pod (partly because I know I have another one that sometimes causes the backlight on the LCD to come and go) or the transducer does need replacing, only it was behaving itself when it went to the garage.

[mowog]

Exactly same thing happened to my 03 tuscan recently. Replaced speedo sensor and everything now OK. Sensor is around £80 -90 IIRC.

[Tuskaa 7]

Exactly the same happened to me. New transducer at £90 plus fitting and all is now fine!

[ec1 eex]

Were your's playing up intermittently as well?

[mowog]

It started out intermittently and then went to 200+ mph! It put 3,000 miles plus on the odometer before I could get it sorted but I've not figured out away of getting these miles back yet unless I remove the speed sensor fuse for 6-9 months (it makes the indicators flash twice as fast if you remove it!)

[tmasse]

Got the same issue with the Speedo and the Digital screen.
Got the sensor changed and the Digital screen replaced: works perfect.

And got the same problem with the Diag "L"...
Lights left on for a night, jump plug: no luck.
Left the country for a week, came back, tried again, still no luck, the immobiliser would not let it go, and as I wasn't sure, I tried pushing it once, and it gave me the Diagnostic code "L"...

I might try to unplug the battery to sort out the immobiliser then. I'm just a bit reluctant as I'm not sure to understand what you meant by "but at the same time should have reset the ECU".
Did it reset the ECU?
Or didn't do it?

T

[ec1 eex]

I referred to resetting of the ECU meaning that this wasn't the cause of my speedo problem.

When my immobiliser needed resetting, the red light to the left of the steering wheel was constantly lit. Removing the earth terminal on the battery made this light go out almost immediately. Once the battery was reconnected, all was fine.

[Chalky White]

Just had a new LCD screen fitted so I can actually read the digital Speedo. I still have a problem with the Analogue Needle which seems to need a rest after about 30 mins and returns slowly to zero. Turning off the ignition and turning it on again seems to reset it. Anyone else had the same problem? what was the fix?

[J_E_T]

I had a problem recently where the needle stuck at 70 as I slowed down. After starting again, the dial moved as normal, but from 70 instead of 0 !! Made for some impressive pictures though .. 70mph suddenly became 140mph (etc.) :-)

Came back to the car the next day and it had settled back to 0 and been fine since. I do get the dodgy readings sometime where the needle is reading 10mph + more than the digital display.

[tmasse]

Chalky White said:

I still have a problem with the Analogue Needle which seems to need a rest after about 30 mins and returns slowly to zero. Turning off the ignition and turning it on again seems to reset it. Anyone else had the same problem? what was the fix?

Yep I do.
Got the LCD changed and the rear axis speed sensor sorted too (the needle was always at 0).

But now, the needle would go up, but not fully down, then up again with speed, then down but not enough, and so on. So after a while you endup parking the car and reading 70 mph even though you are motionless!

I spoke to my TVR garage and he said it could be sorted. Probably a setup to do on a microchip behind the LCD block.
I've planned to do it as soon as I can start the bloody machine (see my post above)

Edited by tmasse on Friday 27th July 17:11

[tmasse]

Just bumped into intersting post from Tuscan Bev in this topic ("Strange fault codes&quot:
http://www.pistonheads.co.uk/gassing/topic.asp?h=0...

So, for L and K he gives this:

L - Erratic road speed sensor input
K - Fuel level sensor open circuit

Please see his post for full list of diag codes.